Retrofit Telestart T90 on T5GP ThermoTopC: recognized, but does not start
- Thread starter Peterb84
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enkor
New Member
I have successfully started Webasto with esp32 using this ugly homemade circuit.
I used this interface GitHub - stuartpittaway/WebastoWBUSInterface: Hardware circuit diagram for interfacing to the Webasto WBUS interface from a PC/Arduino . It would be a lot of easier to use L9637D, but I had all the parts for the circuit at home.
Then I used code from this guy as a starting point.
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I used this interface GitHub - stuartpittaway/WebastoWBUSInterface: Hardware circuit diagram for interfacing to the Webasto WBUS interface from a PC/Arduino . It would be a lot of easier to use L9637D, but I had all the parts for the circuit at home.
Then I used code from this guy as a starting point.
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Well done! What sw did you use? Does it emulate w-bus?
enkor
New Member
There is no need for emulation. W-bus is standard k-line protocol. And with L9637D (or homemade) you can use it with arduino/esp32 (with additional level shifter) uart interface. So you are just sending/receiving messages over serial.
These guys reverse engineered the w-bus protocol and it is well documented W-Bus library and applications
I'm only sending message for turning webasto on and keeping it alive for specific time. I don't care about the readings from the heater.
I checked everything with oscilloscope before I plugged it in car.
Here is the code for platformio. I just renamed extension to txt instead of cpp.
Very nice (and cheap!!!)
Meanwhile, I have found that allegro has T90 receivers at very reasonable prices, around 30 eur (so you could order it there too if you needed).
So I ordered 4F0909509 (4F0909509A, 4F0909509B). This one doesn't have an R at the end so I assume it will allow analog pins.
What I was very suprised to find out was that VW OEM T90 reciever is compatible with non-VW Webasto egg-shaped remote!!!
This is actually very good news because you have more options to look for a better price.
Here's the kit I put together for VW T5 Multivan (remote and receiver linked successfully and working as intended):
I will test the analog pins later but I am pretty sure they work.
enkor
New Member
I bought FOB 7N0963511 out of curiosity. But I couldn't get it to work. Im able to pair the FOB with the Telestart (I can see its serial number in VCDS.) When I press the ON button then I can see in VCDS that the remote status changed from recognized to ON. It only lasts a few seconds, then it goes back to recognized and nothing happens.
I can see on scope that there is some outgoing communication from Telestart unit. But it seems that webasto is not accepting it, there is nothing shown on Thermotest in protocol.
Coding of webasto unit is 001031 (I changed it from 000031).
My device is still able to start webasto without any problems (I have unplugged it when I testing FOB)
What is wrong that when i press ON and OFF then I have no feedback about setup.
Does anybody encountered this problem ? I don't know what to do more.
I can see on scope that there is some outgoing communication from Telestart unit. But it seems that webasto is not accepting it, there is nothing shown on Thermotest in protocol.
Coding of webasto unit is 001031 (I changed it from 000031).
My device is still able to start webasto without any problems (I have unplugged it when I testing FOB)
What is wrong that when i press ON and OFF then I have no feedback about setup.
Does anybody encountered this problem ? I don't know what to do more.
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enkor
New Member
After further research and reading the manual, it seems that I need to set it up before I can use it in the car roof display. Which is the problem because I have a secondary air heater and when I activate the remote option it is related to the air heater. Thus Im not able to set the settings for the webasto.
It seems that Telestart T91R needs to cooperate with other VW systems.
It seems that Telestart T91R needs to cooperate with other VW systems.
According to my info
4F0909509, 4F0909509A, 4F0909509B, 7N0963513, 7N0963513A, 7N0963513B are all compatible. Remotes are definitely compatible as well between all of them - tested.
There's also 1K0963513A - T91 without the R and I think it should be compatible too.
As was discussed before, R might be missing the ability to use the extra pins to turn on the heater. In other word, usage only with remote, custom button implementation not possible. If you're around Prague some time, PM me, I have the 1K0963513A unit that we could test.
enkor
New Member
I tried 4F0909509 and the result is the same. It receives signal but it will not turn the heater on. Strange is that the t90 should be able to send settings information to the FOB, but the FOB does not show anything. It just receives signal when i press ON.
Anyway, I'm giving up and going back to my Arduino solution
Anyway, I'm giving up and going back to my Arduino solution
As a quick and dirty solution, for a couple of bucks you can get a fob and receiever on ali and it will work with your arduino unit.I tried 4F0909509 and the result is the same. It receives signal but it will not turn the heater on. Strange is that the t90 should be able to send settings information to the FOB, but the FOB does not show anything. It just receives signal when i press ON.
Anyway, I'm giving up and going back to my Arduino solution
This looks great!! Perhaps even better for simply adding telestart to a Webasto. I was not planning on using an expensive VW fob anyway, but an Aruidno/ESP processed cheap 433Mhz generic fob.
The project seems pretty straightforward with the code for Arduino available. Thanks for sharing your ESP32 code! Could I however ask you what 2 modules you have added on your PCB on the left (with the "ugly" circuit on the right)? They seem to get GND, RX/TX, and 3V3 from your ESP32 board before going to the K-line conversion? Are they voltage regulators or amplifiers or so?
enkor
New Member
green board is step-down to 5V from 12V.
blue board is level shifter from 5V to 3.3V, you will not needed for Arduino. But ESP has 3.3V logic.
I also bought some L9637D chips, because I've got some interference with this homemade board and sometimes It can get very messy readings (however for just starting the webasto it works fine). But I did not have time to test them yet.
blue board is level shifter from 5V to 3.3V, you will not needed for Arduino. But ESP has 3.3V logic.
I also bought some L9637D chips, because I've got some interference with this homemade board and sometimes It can get very messy readings (however for just starting the webasto it works fine). But I did not have time to test them yet.
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